Specification Sheet: Alloy C276 - Sandmeyer Steel

1 Alloy c276 (UNS N10276) is an austenitic nickel-molybdenum-chromium Alloy with a small addition of tungsten. It is one of the premier corrosion resistant materials available for process industries. Alloy c276 has excellent corrosion resistance in both oxidizing and reducing combination of the high molybdenum and chromium content, along with the addition of tungsten, make Alloy c276 highly resistant to chloride stress corrosion cracking, pitting, crevice corrosion and general c276 can operate in oxidizing atmospheres up to 1900 F (1038 C), however, the Alloy lacks sufficient chromium content to operate successfully in the most strongly oxidizing environments like hot, concentrated nitric low carbon content of Alloy c276 enables the Alloy to be utilized in the as-welded condition.

2 It cannot be hardened by heat treatment, but can be hardened by cold working. The Alloy has a higher work-hardening rate than the austenitic stainless steels which should be taken into c276 can be easily welded and processed utilizing standard shop fabrication practices for austenitic stainless steels and nickel based ..B 575 ASME ..SB 575 Specification Sheet: Alloy c276 (UNS N10276) W. Nr. Nickel-Molybdenum-Chromium Alloy with Excellent Corrosion Resistance in both Oxidizing and Reducing EnvironmentsAlloy c276 06 Steel COMPANYONE Sandmeyer LANE PHILADELPHIA, PA 19116-3598800-523-3663 +1-215-464-7100 FAX +1-215-677-1430 Providing Solutions, With Materials andValue Added Products, for Process IndustriesApplications Air Pollution Control flue gas desulfurization systems stack liners, absorbers, ducts, dampers, stack gas re-heaters and fans Chemical Processing heat exchangers, pressure vessels, tanks, evaporators, piping, flanges and fittings.

3 Pumps and valves Oil and Gas Production sour gas service components Pharmaceutical Production reactor vessels, piping, flanges and fittings, pumps and valves Pulp and Paper bleaching vessels and digestors Waste Treatment incinerators for toxic, industrial and municipal wastePhysical PropertiesDensity lbs / in3 g /cm3 Modulus of Elasticity x 106 psi GPaMelting Range 2415 2500 F 1325 1370 CSpecific Heat BTU/lb- F @ 70 F 427 J/kg- C @ 20 CThermal Conductivity 212 F (100 C) BTU-in/ ft2-hr- F W/m- CElectrical Resistivity 51 Microhm-in at 75 F Microhm-cm at 24 CMean Coefficient of Thermal Expansionin/in F cm/cm C 200 93 x 10-6 x 10-6 400 204 x 10-6 x 10-6 600 316 x 10-6 x 10-6 800 427 x 10-6 x 10-6 Temperature Range F CChemical AnalysisWeight % (all values are maximum unless a range is otherwise indicated) Nickel Balance Manganese Molybdenum min.

4 Max. Carbon Chromium min. max. Vanadium Iron min. max. Phosphorous Tungsten min. max. Sulfur Cobalt Silicon ResistanceAlloy c276 is one of the premier corrosion resistant materials that performs exceptionally well in both oxidizing and reducing environments. It resists chloride stress corrosion cracking, pitting, crevice and general corrosion. The Alloy is also resistant to carbide precipitation during welding enabling it to be utilized in the as-welded chemical processing applications, the Alloy has exceptional resistance to sulfuric, hydrochloric, formic, acetic and phosphoric acids.

5 Alloy c276 performs well in environments containing acid chlorides, solvents and acetic anhydride, The Alloy is one of the few grades that withstands wet chlorine gas, hypochlorite and chlorine dioxide solutions. Alloy c276 is highly resistant to concentrated solutions of oxidizing salts including iron and copper chloride. It also performs well in seawater, especially under crevice conditions where other frequently used alloys such as stainless Steel , Alloy 400 and Alloy 625 operating conditions of flue gas desulfurization systems offer a challenging environment for corrosion resistant materials. Scrubber liquors and gas condensates often contain chlorides.

6 Alloy c276 has been shown to withstand higher chloride levels than other grades before the onset of localized corrosion in these c276 is used extensively in the recovery and processing of sour natural gas which contains hydrogen sulfide along with carbon dioxide and chlorides. Carbon and Alloy steels cannot withstand this corrosive environment. They are subject to failure by sulfide stress cracking or stress corrosion cracking. The rich chemistry of Alloy c276 makes it resistant to sour environments even at high temperatures in deep wells. Mechanical PropertiesTypical Values at 68 F (20 C) Yield Strength Ultimate Tensile Elongation Hardness Offset Strength in 2 in.

7 Psi (MPa) psi (MPa) % (max.) 41,000 283 100,000 690 40 100 Rockwell BMaximum depth of attack by crevice corrosion after exposure to quiescent seawater at 85 F (29 C) for 180 days as a function of PREN**PREN = % Cr + (% Mo + % W = % Nb) + 30 (% N)Maximum Depth of Attack (mm) , F37532527522517512577212 Temperature, C20015010050 Boiling Point CurveAlloy 686 Alloy 622 Alloy C-276 Boiling Point CurveAlloy 925 Alloy 718 Alloy 25-6 MOAlloy 925 Alloy 718 Alloy 25-6 MOAlloy 625 Alloy 686 Alloy 622 Comparitive behavior of Ni-CR-MO alloys in sulfuric acid. The iso-corrosion lines indicate a corrosion rate of 20 mpy ( mm/a).

8 Acid Concentration, %0204060 PRENA lloy C-276 Alloy C-276 Alloy 686 Alloy 686 Alloy 622 Iso-corrosion chart for Alloy C-276 in hydrochloric , FTemperature, C1251007550 HCL Concentration, %250212200150100<5 mpy(< mm/a)5 20 mpy( mm/a)20 50 mpy( mm/a)50 200 mpy( mm/a)200 300 mpy( mm/a)Boiling Point CurveBoiling Point CurveCorrosion resistance in hydrochloric acid. The isocorrosion curves show tempatures and concentrations above which the corrosion rate exceeds mm/a (20 mpy).Boiling Point CurveBoiling Point CurveAlloy 22 Alloy 22 Alloy 625 Alloy 625 Alloy C-276 Alloy C-276 Alloy 686 Alloy 686020401030 Temperature, FTemperature, C21220017515012510077 HCL Concentration, %120110100908040506070202530 Iso-corrosion chart for Alloy C-276 in phosphoric Acid Concentration, %Temperature, F350300250212200150100 Temperature, C1501251007550020406080103050705 25 mpy( mm/a)Boiling Point CurveBoiling Point Curve<5 mpy(< mm/a)<5 mpy(< mm/a)Corrosion Tests* in Hydrogen Fluoride Duration, 36 Hours.

9 Temperature 932 1112 F (500 600 C)CommentsMATERIAL Alloy C-276 ( ) Iridescent tarnish film Alloy 600 ( ) Iridescent tarnish film Nickel 200 9 ( ) Black film Nickel 201 14 ( ) Black film Alloy 400 13 ( ) Adherent dark film Alloy K-500 16 ( ) Adherent dark film 70/30 Copper-Nickel 16 ( ) Adherent dark film Corrosion Rate, mpy (mm/a)* 7 lb HF per hour at 4 psig was passed through a laboratory furnace for hydroflourination of metal Pitting or Crevice Attack, mils (MM), in FGD Scrubber Slurrya Alloy Quencher Absorber Absorber Outlet Bypass Outlet Duct Duct 316L Stainless Steel 22 ( ) 21 ( ) 35 ( )b 35 ( )b 12 ( ) 317LM Stainless Steel 20 ( ) 22 ( ) 29 ( ) 33 ( ) 29 ( ) Alloy 825 15 ( ) 33 ( ) 39 ( ) 50 ( )b 10 ( ) Alloy 625 <2 (< ) 10 ( ) 11 ( ) 7 ( ) nil Alloy C-276 nil nil <2 (< ) nil nila 6-month exposure at 126 F (62 C), pH , 5000 ppm chlorides.

10 B COMPANYF abrication DataAlloy c276 can be easily welded and processed utilizing standard shop fabrication practices for austenitic stainless steels and nickel based Forming The hot-working temperature range for Alloy c276 is 1600 2250 F (870 1230 C). The Alloy should be water quenched after hot working. Heat treatment is recommended after hot working to ensure maximum corrosion Forming Alloy c276 should be in the annealed condition for cold working. The Alloy has a higher work-hardening rate than the austenitic stainless steels which should be taken into consideration. An in-process anneal may be necessary with a high degree of cold working.